/Engine/Source/Editor/UnrealEd/Classes/Editor/EditorEngine.h
Finds a brush builder of the provided class. If it doesnt exist one will be created
The found or created brush builder
[UBrushBuilder](API\Runtime\Engine\Engine\UBrushBuilder) * FindBrushBuilder ( [UClass](API\Runtime\CoreUObject\UObject\UClass) * BrushBuilderClass )